Biochar added to pasture soil decreases Nitrous Oxide Emissions
A study recently completed in New Zealand found that adding biochar to the soils of pastures where Cows (ruminants) were grazing sharply decreased the excess nitrous oxide from the cows urine. It appears that the biochar helps the soil absorb the extra gasses although long term testing of the effect of cow urine and pasture with biochar still needs to be done.
You can get the Full Report, or read the Abstract from the American Society of Agronomy web site:
Biochar Incorporation into Pasture Soil Suppresses in situ Nitrous Oxide Emissions from Ruminant Urine Patches
by Arezoo Taghizadeh-Toosi,Tim J. Clougha, Leo M. Condronab, Robert R. Sherlocka, Craig R. Andersonb and Robin A. Craigiec
Published in the Journal of Environmental Quality Vol. 40 No. 2, p. 468-476
A summary is here: Can Biochar Help Suppress Greenhouse Gases?